1. Field of the Invention
The present invention relates to a lamination apparatus and a laser-induced thermal imaging (LITI) method using the same and, more particularly, to a lamination apparatus for performing a lamination process of a donor substrate in an inert gas atmosphere and an LITI method using the same.
2. Description of the Related Art
Since an organic light emitting display (OLED) among flat panel displays has a fast response speed of not more than 1 ms, low power consumption, and a wide viewing angle due to an emissive display, the OLED has an advantage as a medium for displaying a moving picture regardless of device size. In addition, since the OLED may be fabricated at low temperature and may be readily fabricated on the basis of conventional semiconductor manufacturing processes, the OLED is attracting public attention as a next generation flat panel display.
The OLED is generally classified into a polymer device using a wet process and a small molecular device using a deposition process depending on materials and processes for fabricating an organic light emitting diode.
In the case of the polymer OLED, the device is manufactured by depositing an organic layer having an emission layer on a substrate having a pixel electrode using an inkjet printing method or a spin coating method, and forming an opposite electrode.
In addition, in the case of the small molecular OLED, the device is completed by depositing an organic layer having an emission layer on a substrate having a pixel electrode using a deposition method, and forming an opposite electrode.
In the case of the inkjet printing method among methods of patterning the polymer and small molecular weight emission layers, organic layers except for an emission layer should be made of restricted materials, and there should be a troublesome process of forming a structure for inkjet printing on a substrate.
In addition, when the emission layer is patterned using a deposition process, it may be difficult to manufacture a large-sized display due to use of a metal mask.
In order to substitute for the patterning method, a laser-induced thermal imaging (LITI) method has been recently developed.
The LITI method is a method of converting a laser emitting from a light source to heat energy, and transferring a pattern forming material to a corresponding substrate using the converted heat energy to form a pattern. In order to perform the LITI method, a donor substrate, at which a transfer layer is formed, a light source, and a substrate as a subject are required.
In performing the LITI method, the donor substrate has a shape of covering the entire substrate as a receptor, and the donor substrate and the substrate are fixed on a stage.
Then, the fixed substrate is subjected to a laminating operation, and bubbles or misalignment may occur between the donor substrate and the substrate due to poor adhesion there between when the substrate and the donor substrate are moved along the lamination direction during the laminating operation. As a result, there may be problems while patterning an emission layer.
In addition, there may be problems that particles are introduced from the exterior into a chamber where the stage is located. The particles exist on the transfer layer to generate failures of the display device such as spots or pixel defects in an emission region, and deteriorate display performance.